The present invention relates to stringed musical instruments having finger boards including frets, and relates particularly to setting up such a musical instrument by adjusting the positions of the open strings in order to improve the ability of the strings of the instrument to vibrate at the intended frequencies as accurately as practical throughout the entire designed tonal range of each string, and to have the strings located so as to be as comfortably playable as possible for a particular musician.
Stringed instruments such as lutes, guitars, banjos, and mandolins have several strings extending parallel with one another and held in tension, extending between two fixed supports, a nut at an outer end of a neck and a bridge located on a body from which the neck extends. The distance between the nut and the bridge is the open length of a string and thus establishes its fundamental tone when the string is held in tension. A fingerboard including frets is included in the neck and may extend over the body. A string can be made to sound a note higher than its fundamental tone by fretting the string, that is, by pressing the string against the fingerboard adjacent to one of the frets.
Several factors contribute to determine whether a fretted string will produce the desired note. The material of which the string is made, the action height of the instrument (the distance between an open string and the frets), the thickness, or gauge, of the string, the tension of the string when it is tuned to its intended fundamental tone and the length of the open string, all affect the frequency at which the string vibrates when the string is pressed against a fret located on the fingerboard. A musician may have a preference for particular types of strings, for a particular spacing between strings, or for the location of an outermost one of the strings with respect to a side of the fingerboard. Even the structure of the body of the instrument has an effect, since the top of the body is effectively a sound board that vibrates and thus may make a string vibrate as if it were a little longer than the actual distance between the nut and the bridge.
While various adjustable guitar bridges and nuts are known, they usually present a technical or mechanical appearance that detracts from the traditional appearance of a guitar or other acoustic stringed instrument. What is desired, then, is a stringed instrument having the capacity for its intonation to be optimized string-by-string, yet having a traditional, non-mechanical appearance, and a method of setting up such an instrument according to preferences of a particular musician.